Negative-plate holder for cameras.



No. 698,73I. PatenteaApr. 29, |902.y

K. NELsoN.

NEGATIVE PLATE HOLDER FDH CAMERAS.

(Application med Feb.' s, 1902.) (No Model.) 2 Sheets'-Sheei l.v

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No. 698,731. Patented Apr. 29, |902.

K. NELSON. NEGATIVE PLATE HOLDER FOR CAMERAS.

(A )plicntion filed Feb. 8. 1902.)

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KNUD NELSON, OF CHICAGO, ILLINOIS.

NEGATIVE-PLATE HOLDER FOR CAMERAS.

SPECIFICATION forming part 0f Letters Patent No. 698,731, dated April 29, 1902.

Application filed February 8, 1902. Serial No. 93,151. (No model.)

To (tu wiz/0721. t may concern.:

Be it known that I, KNUD NELSON, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Negative-Plate Holders for Cameras, of which the following, when taken in conriection with the drawings accompanying and forming a part hereof, is a full and complete description, sufficient to enable those skilled in the art to which it pertains to understand, make, and use the same.

The invention relates to what are known in the art as curtain plate-holders for cameras, such plate-holders being ordinarily used in large cameras,wherein negative-plates of different sizes are inserted for use.

In practice I have found that where a negative-plate of any considerable size, as, say, one larger than four by five inches, is used and a spring is pressed against such plate to vhold it in a determined plane the face of such negative-plate will not be all in the same'plane-that is, the platel will spring; and the object of this invention is to obtain a plate-holder of the kind named wherein negative-plates of different sizes and constructed of glass,which are placed therein,will be held in a determined plane without the use of a spring or` any other thing pressing upon the face of the plate.

A further object of the invention is to obtainv a plate-holder of the kind described1 wherein no adjustment is required of the several parts in putting in place therein negative-plates of different sizes.

A further object of the invention is to obtain a plate-holder of the kind named which will be easy to operate, simple in construction, durable, and not liable to get out of order.

A further object of the invention is to obtain a plate-holder of the kind named which will be sightly, effective inits protection of a negative-plate from actinic rays, not cumbersome, and easily handled.

In the drawings referred to and forming a part of this specification, Figure 1 is a front elevation of a plate-holder embodying this invention With the curtain thereof closed on the front of the holder and such curtain broken away to disclose to view the operaby the arrows.

tive parts of the holder, such operative parts being in the position assumed thereby when no negative-plate is contained in the holder.

Fig. 2is a vertical sectional view on line 2 2 of Fig. l viewed in the direction indicated Fig. 3 is a front elevation, on an enlarged scale, `of the operative parts of-one end of the plate-holder with a portion of the front of such part broken away to expose to view the movable parts thereunder. Fig. 4: is an elevation, also on an enlarged scale, of the several parts illustrated in Fig. 3 viewed in a position at right angles to the View obtained in such Fig. 3. Fig. 5 is a horizontal sectional view on line 5 5 of Figs. 3 and l-viewed in the direction indicated by the arrows; and Figs. 6 and 7 are front elevations, respectively, ofA right and left hand gear-racks, forming elements in the plateholder embodying this invention. Fig. Sis an enlarged view of a section of the gear-racks and engaging wheels.

A reference-letter applied to designate a given part is used to indicate such part throughout the several iigures of the drawings wherever the same appears.

' A is the frame of the plate-holder and comprises the top bar d, bottom bar d', and side bars a2 a3. f

ctAk is the raised portion of the front of the frame A, which is ordinarily made on plateholders to obtain a light-tight joint between the plate-holder and the camera with which the plate-holder is used.

B is a curtain, constructed substantially in the same way as a roller-top to a desk, but light-proof.

b is the handle of the curtain, by means of which handle the curtain is moved in grooves C C from the front of the frame A (the position of such curtain which is shown in Fig. l) to the back of such frame, (the position of such curtain which is shown in Fig. 2.)

When a negative-plate is t0 be inserted in the plate-holder embodying this invention or is to be taken therefrom, the curtain B is preferably moved to the back of the frame, as is shown in Fig. 2 of the drawings, the negative-plate being inserted in and taken from such plate-holder from the front thereof.

D is a removable back to the plate-holder.

When removable back D is taken from the plate holder, a negative plate may be inserted in or taken from such plate-holder from the back thereof upon moving the curtain B to the front of the plate-holder. The back D constitutes the protection to the negative-plate contained in the plate-holdell from actinic rays when curtain B is in front ol' the plate-holder, as in Fig. I. Back D is not required to be removed in the use of this plateholder at any time, the negative-plates being removable from the plate-holder through the front thereof,asis hereinafterfullydescribed; but as plate-holders have heretofore been constructed so that the back D is necessarily taken out to remove the negative-plate therein orto put a negative-plate thereinto I have so constructed the plate-holder embodying this invention as to permit its operation in the same way, although I deem the preferable way of operating the plate-holder to be the insertion of a negative-plate and the removal thereof from such plate-holder th rough the front, with the curtain C in the position illustrated in Fig. 2 of the drawings. To remove the back D from frame A, such back is slid until shoulder d is close to contact with the under side of bar d, and tongue d' is contained in groove a5, at which time the tongue cl2 on the under or bottom edge of the back D is not in engagement with the groove a on the bottom of such back.

E, Figs. I and 2, is a rib attached to the :forward or inner side of back D. Rib E is provided with pin-holes into which may be inserted a pin e, as is indicated by broken lines in Fig. l, such pin being used when a number of negative-plates of agiven size are to be inserted and taken from the plate-h older, at which time it is desired that bars F F shall be held apart from each other, so as not to approach (beyond pin e) to their closed position-that is, to the position illustrated in Figs. I and 2. The open position of bar F, above referred to, is indicated by the broken lines F2 in Fig. I.

A negative-plate is held in the plate-holder embodying this invention between the bars F F, and such bars are arranged to be movable laterally in frame A to and from each other. To insure the placing of the negative-plate in the plate-holder in the determined plane therefor, I provide the triangular-shaped grooves fj" in bars F F', respectively, and to maintain the negative-plate in proper position in the plate-holder to the right and left Iprovide the steps fzff flf -l on the bar F. To maintain such negative -plate in proper position in the plateholder relative to being above and below a horizontal line through the center of the plateholder, the bars F F are respectively attached to the racks G Gand G' G'. The racks G G are attached at one end of bars F FQ and the racks G t' are attached to the opposite ends of such bars F F', and also I place the gear-wheels II II to intermesh with the teeth of such racks.

72, 7L are the pivots on which the gears II II are respectivelyloosely mounted. Such pivots 7L 7L may well consist of ordinary woodscrews.

h 7U are washers, also loosely mounted on pivots 7L 7L. Vashers 7L' 7L are used to hold the racks G G and G G' in place against the U-shaped bars I I,with the teeth of such racks in engagement with the teeth of the gearwheels 7ly 7i'.

The U-shaped bars I I are preferably made of metal and are attached, as by screws .I J, rigidly to the side bars 1,2 d3, respectively, of frame A. The racks G G G Gand the gearwheels II II are preferably made of alu minium, as such metal is well adapted to withstand the acid which in use is frequently brought in contact therewith.

To hold the bars F F against the upper and lower edges of the negative-plate placed in grooves ff', I provide springs K K at the ends of one of such bars F F. I have shown in the drawings such springs K K attached at one end to the bars @2613, respectively, as at 7s, and at the other end attached to the lower bar F, as at 7c. (See Figs. l and 4.)

It will be observed in Fig. S that the distance of pivots 71 7l from each other is such relative to the size of gear-wheels II II and racks G G (or racks G G') and the size of the teeth on the wheels and racks that when the teeth of one of the gear-wheels II II are well engaged, say, with one of the teeth of such wheelon the horizontal center of the pivot that the teeth of the other one of such gear-wheels II II will be above and below such horizontal center when engaging with the rack and a tooth of the rack will be on such horizontal center.

I find that by using two gear-wheels. II II, arranged as described and shown in Fig. 8, a very even action is obtained between the bars F F, so that when one of such bars-as, say, bar F, being the one to which one end ofthe springs K K are attached-is forced laterally away from the centerline of the plate-holder and away from the other one of such bars such lateral movement is transmitted by means of the racks G G and G G and gearwheels II I-I to the other one of such bars, and such other bar F is thereby moved laterally an equal distance from such horizontal line passing through the center of the plate-holder.

To enable an operator to readily-control a negative-plate when such plate is being placed in or taken from bars F F, I cut the recess L into bar F. (See Figs. I and 2).

The mannerof operating the plate-holderembodying this invention is: IVhen a negativeplate is to be inserted in the plate-holder in the preferable way, the curtain Il is putinto the position illustrated in Fig. 2 of the drawings. The lower edge of the negative-plate is then placed in groovef of bar F and such negative-plate is pressed downward, thereby forcing the bar F downward and the bar F upward. This operation is continued until IOC IIO

eesfzei the bar F is raised a sufficient distance to permit the insertion of the upper edge of such negative-plate in groove f of bar F. The downward pressure on the negative-plate is then released and the bar F. is raised by the resilience of the springs K K, thereby drawing-bar F downward, thereby holding such negative-plate in place in groovesff. To take the negative-plate out of the plate-holder, such negative plate may again be forced downward by placing the hand on the upper edge thereof in recess L until such upper ledge is out of the groove f and then bringing such upper edge forward out of such groove and raising the plate from bar F. NVhen the plate is in the holder embodying this invention, the curtain Bis closed thereover in the ordinary manner of closing the curtain of the plate-holder of this kind over the negative-plates when the plate-holder is being placed on or taken from a camera.

By attaching the springs K K to the lower one of the bars F F when a negative-plate is inserted between the bars by placing the lower edge of such negative-plate in the groove in the lower one of such bars F F and forcing such negative-plate and lower bar downward a very smooth and even action of bars F F is obtained, both because of the fact that two gear-wheels engage with each of the racks G G G G' and because there is no resistance to the upward movement of the upper one of the bars except the weight thereof, while after the negative-plate is inserted between the bars and the bars released such springs will draw the lower bar upward and by means of the racks and interposed gear-wheels will also draw the upper bar downward to hold the negative-plate firmly in place.

Having thus described my invention and the construction and operation of an apparatus embodying the same, what Iclaim as new, and desire to secure by Letters Patent, is-

l. Ina negative-plate holder the combination of a frame, bars arranged to move laterally in the frame, geared racks secured to the ends of the bars, a plurality of gear-wheels pivotally mounted between adjacent racks to engage with the teeth of such racks and springs attached at one of the ends thereof to the ends of one of the bars, with the other of the ends of such springs attached to the frame; substantially as described.

2. In a negative-plate holder the combination of a frame, U-shaped Vbars attached to the inner sides of the frame, the bars arranged to lnove laterally in the frame, geared racks secured to the ends of the barsfto move longitudinally in the U-shaped bars, a plurality of gear-wheels pivotally mounted between adjacent racks to engage with the teeth of such racks and washers rotatably mounted on the pivots of the gear-wheels to maintain the geared racks in place; substantially as vdescribed.

3. In a negative-plate holder the` combination of a frame, U -shaped bars attached to the inner sides of the frame, cross-bars arranged to move laterally in the frame, geared racks secured to the ends of the cross-bars such geared racks arranged to slide longitudinallyin the U-shaped bars, a plurality of gear-wheels pivotall y mounted between adj acent racks to engage with the teeth of such racks, washers rotatably mounted on the pivots of the gear-wheels to maintain the geared racks in place, springs attached at one end, respectively, to the ends of one of the bars and an attachment at the other end to the frame, the cross-bars respectively provided with grooves on adjacent sides; substantially as described.

4. In a negative-plate holder the combination of a frame, plate-holding bars arranged to move laterally in the frame, geared racks secured to the ends of the bars and a plurality of gear-wheels pivotally mounted between adjacent racks to engage with the teeth of such racks, such plate-holding bars respectively provided with grooves on the inner side thereof, such grooves triangular in crosssection with the front face thereof substantially vertical when the plate-holder is in an upright position; substantially as described.

5. In a negative-plate holder the combination of a frame, plate-holding bars arranged to move laterally in the frame, geared racks secured to the ends of the bars, a plurality of gear-wheels pivotally mounted between adjacent racks to engage with the teeth of such racks, and springs attached at one end respectively to the ends of one of the bars and at the other end to the frame, such plate-holding Abars respectively providedwith grooves on the inner side thereof, such` grooves triangular in'cross-section with the front face thereof substantially vertical when the plateholder is in an upright posi tion; substantially as described.

6. In a negative-plate holder the combination of a frame, plate-holding bars arranged to move laterally in the frame, one of such bars provided with steps arranged in pairs at equal distance from ythecenter of the bar, such steps respectively provided with grooves on the inner sides thereof, such grooves triangular in cross-section with the front face thereof substantially vertical when the plateholder is infan upright position and the other bar-provided with a recess on its front face and with a groove on its inner side, such groove corresponding in cross-section with the first-named groove, geared racks secured to the ends of the bars, a plurality of gearwheels pivotally mounted between adjacent racks to engage with the teeth of such racks, and springs attached at one end respectively to the ends of one of the bars and at the other end to the frame, such plate-holding bars movable in opposite directions; substantially as described.

y7. In-a negative-'plate holder the combination of a frame, plate-holding bars arranged to move laterally in the frame, one of such IOO IIO

bars provided with steps arranged in pairs at equal distance from the center of the bar, such steps respectively provided with grooves on the inner sides thereof, such grooves triangular in cross-section with the front face thereof substantially vertical when the plateholder is in an upright position and the other bar provided with a recess on its front face and with a groove on its inner side, such groove corresponding in cross-section Wit-h the first-named groove, geared racks secured to the ends of the bars, a plurality of gearwheels pivotally mounted between adjacent racks to engage with the teeth of such racks, and springs attached at one end respectively to the ends of one ofthe bars and at the other end to the frame, a back, a rib in the inner face ofthe back, such rib provided with holes and a pin removably iitting'such holes; substantially as described.

S. In anegative-plate holder the combination of afraxne, plate-holding bars arranged to move laterally in the frame, one of such bars provided with steps arranged in pairs at equal distance from the center of the bar,

I such steps respectively provided with grooves on the inner sides thereof, such grooves triangular in cross-section with the front face thereof substantially vertical when the plateholder is in an upright position and the other bar provided with a recess on its front faee and with a groove on its inner side, such groove corresponding in cross-section With the irst-narned groove, U-shaped bars attached to the inner face of the sides of the frame, geared racks secured to the ends of the bars to slide longitudinally in the U- shaped bars, a plurality of gear-Wheels pivotally mounted between adjacent racks to engage with the teeth of vsuch racks, Washers rotatably mounted on the pivots of the gear- Wheels to hold the racks in place, and spring attached at one end respectively to the ends of one of the bars and at the other end to the frame; substantially as described.

KNUD NELSON.

In presence of ANNA NELSON, CHARLES TURNER BROWN. 

